Ternary Ta2PdS6 Atomic Layers for an Ultrahigh Broadband Photoresponsive Phototransistor

2D noble-transition-metal chalcogenides (NTMCs) are emerging as a promising class of optoelectronic materials due to ultrahigh air stability, large bandgap tunability, and high photoresponse. Here, a new set of 2D NTMC: Ta2PdS6 atomic layers is developed, displaying the excellent comprehensive optoelectronic performance with an ultrahigh photoresponsivity of 1.42 x 10(6) A W-1, detectivity of 7.1 x 10(10) Jones and a high photoconductive gain of 2.7 x 10(6) under laser illumination at a wavelength of 633 nm with a power of 0.025 W m(-2), which is ascribed to a photogating effect via study of the device band profiles. Especially, few-layer Ta2PdS6 exhibits a good broadband photoresponse, ranging from 450 nm in the ultraviolet region to 1450 nm in the shortwave infrared (SIR) region. Moreover, this material also delivers an impressive electronic performance with electron mobility of approximate to 25 cm(2)V(-1)s(-1), I-on/I-off ratio of 10(6), and a one-year air stability, which is better than those of most reported 2D materials. Our studies underscore Ta2PdS6 as a promising 2D material for nano-electronic and nano-optoelectronic applications.

Automated summary

The newly developed 2D noble-transition-metal chalcogenides Ta2PdS6 exhibit excellent optoelectronic performance with high photoresponsivity and detectivity, as well as a broadband photoresponse. Additionally, the material shows impressive electronic performance and air stability.